There is a significant need for new insights into mechanisms of brain damage due to trauma. Damage due to different types of head trauma, from focal contusions to concussions, requires new thinking about methods and outcomes to provide windows for treatment to ameliorate this major risk to children and adults, as well new preventative measures. To address this major and growing need we plan to utilize novel 3D brain-like tissues in vitro, coupled with animal studies, to correlate markers and mechanisms of injury and response. Our hypothesis is that 3D mouse and human brain-like tissues with structural and functional features mimicking in vivo conditions will provide physiologically-relevant readouts for the study of brain function and responses to mechanical damage to study mechanisms involved in traumatic brain injury and repair. Such correlations will provide new and important insight into pathways activated by injury, how the type of injury effects different pathways, how the brain heals in response to these different pathways, and to help identify new leads for intervention and treatments. The coupling of in vitro 3D tissues (rodent and human) with in vivo rodent studies, impacted by different types of damage (e.g., inertial and weight drop), will provide a comprehensive assessment of outcomes not previously pursued, while also improving translational relevance. The availability of tissue models that sustain structure and function for months allows for both acute and chronic assessments of outcomes (genetic, biochemical, metabolomics, electrophysiological). These readouts will offer unprecedented insight and interpretation of cause and effect to these types of injuries. Our initial insight into mechanisms, such as involving Akt and mTOR activation, will provide suitable starting points for further study, while transcriptomics will allow for the identification of new leads. Ultimately, comparing transcriptome responses between the in vitro and in vivo models, along with the other readouts planned, and doing so in both acute and chronic temporal responses in vitro and in vivo, should provide unprecedented new insight into damage effects and modes for intervention. All of the plans are supported with extensive preliminary data.